Liquid products such as edible oils are often packaged and sold in plastic bottles. Recently, in order to save natural resources there has been a desire to reduce the amount of plastic used to make these bottles. Furthermore, it is also desirable to make bottles that are more readily collapsible to reduce solid waste landfill volume. However, when the amount of plastic used to make a bottle is substantially reduced, the bottles typically become very flexible, to the point that they become bag-like and inconvenient to use and pour from without losing control.
When a plastic bottle contains a product such as an edible oil, the consumer usually grasps the bottle between their thumb and forefinger along the center of the bottle and tilts the bottle along its vertical axis to dispense discrete amounts of product. If the bottle is too flexible and relatively full of product when consumers grasp the bottle will deform, thereby reducing its internal volume and causing some amount of product to flow out of the bottle resulting in uncontrolled dispensing, oftentimes resulting in spilling and messiness. This makes the use of very thin plastic bottles for products such as edible oils impractical. To avoid the foregoing problems, consumers have generally shown a preference for bottles that are relatively rigid. Unfortunately, producing a prior art bottle rigid enough to have good handling and dispensing qualities directly conflicts with the desire t reduce the amount of material used to make the plastic bottle. Most commercially available plastic bottles for liquid consumer products such as edible oils typically have weight/volume ratio, measured in grams of plastic per fluid ounces of the interior liquid containing chamber, of 1.3 or higher. There has been a desire to make a lightweight plastic bottle for such products, which is defined above as a bottle having a weight/volume ratio less than or equal to unity.
One method used in the past to reinforce flexible plastic bottles has been to place an outer shell of paperboard or like material around the flexible plastic bottle to reinforce it. Such containers are commonly referred to as bag-in-boxes. An example of a bag-in-box can be found in commonly assigned U.S. Pat. No. 4,696,840 issued to Skidmore et al. on Sep. 29, 1987. In a similar fashion one could simply place a band of paperboard or other substantially rigid material around the center of the flexible plastic bottle where the user normally grabs it. An example of such a device can be found in Canadian Patent No. 474,542 issued to Gushard on Jun. 19, 1951. Such packages, however, often require additional manufacturing steps, such as an assembly operation, which slows down production time and results in increased costs. Furthermore, these packages may pose environmental problems of their own. The bottles are made of two different materials requiring them to be separated before recycling. Separation may be impractical and/or inconvenient for the consumer.
Another method used in the past to help overcome dispensing problems associated with a flexible plastic bottle is to mold a handle section integral with the bottle itself. However, this solution also poses some drawbacks. For example, a handled bottle is inefficient in the amount of space that is needed to ship and store the bottle prior to use by the consumer. In addition, more material is normally needed. This can actually increase rather than decrease the use of the material and thereby increase the consumption of natural resources. Furthermore, handled bottles, for the most part, can only be manufactured using extrusion blow molding equipment. This normally limits the types of plastic that can be used. Polyethylene terepthalate (PET) is a preferred plastic material for making bottles for liquids not only because it is strong and durable, but also because it is relatively low in cost. Stretch blow molding a handled bottle comprised of PET normally requires two separate molding operations, one for the bottle and one for the handle. This can increase the cost of the bottle and result in increased production time.
One example of a non-handled plastic bottle used for sterile medical liquids can be found in U.S. Pat. No. 3,537,498 issued to Amand on Nov. 3, 1970. Amand discloses a rectangular bottle for sterile medical liquids, said bottle having indented wall sections, often referred to as a pinched-in waist, between the top and the bottom ends. The thickened pinched in waist shown in Amand curves inwardly to provide an indented channel completely encircling the bottle. This channel or pinched-in waist section is allegedly more rigid than the body of the bottle itself because of a combination of the indented geometry and the increased thickness in the pinched-in area. However, the bottle disclosed in the Amand patent is suggested for dispensing intravenous fluids by hanging the bottle upside down, not for dispensing liquids by tilting the bottle along its vertical axis and pouring. While the reinforcing technique disclosed by Amand may be sufficient for handling sterile medical liquids, particularly where the bottle's contents are not dispensed by pouring, it has been found that simply providing increased thickness to a pinched-in waist will not, by itself, give the bottle sufficient rigidity to facilitate mess-free pouring from a bottle liquids typically encountered in a kitchen environment such as cooking oil. Achieving a sufficient degree of rigidity normally requires that the grip area be made so thick that it defeats the purpose of using less plastic to make the remaining portions of the bottle, i.e., there is no appreciable saving in plastic when the entire bottle is weighed.
It is therefore the object of the present invention to provide a non-handled flexible plastic bottle with a unique substantially rigid grip area that overcomes the problems associated with the prior art bottles mentioned above.
It is another object of the present invention to provide such a bottle that is lightweight and therefore requires less material to produce.
It is another object of the present invention to provide such a plastic bottle having non-rigid portions which are readily collapsible, thereby reducing solid waste landfill volume.
It is another object of the present invention to provide such a plastic bottle that retains the basic functional features of a rigid bottle including openability, freshness protection, secure one-handed gripping and pouring, and reliable reclosure.
It is another object of the present invention to provide such a lightweight plastic bottle having a substantially rigid grip area that can be easily grabbed by one hand allowing the user to dispense small or discrete amounts of liquid easily and without loss of control due to collapse of the grip area.
It is another object of the present invention to provide such a lightweight plastic bottle having a substantially rigid grip area so that when the user squeezes the grip area, movement of the bottle towards its interior is substantially reduced and lateral movement of opposing portions of the grip area, relative to each other, is also substantially reduced.
The aforementioned and other objects of the invention will become more apparent hereinafter.